John works as a database designer in ABC Tech. He wants to produce a description of a database
implemented on secondary storage media. Which of the following designs will he implement to
accomplish the task?
A.
Logical database design
B.
Conceptual database design
C.
Database design
D.
Physical database design
Explanation:
Physical database design is the process of producing a description of the database implementation
on secondary storage. It describes base
relations, file organizations, and indexes used to achieve efficient access to data. It also describes
any associated integrity constraints and
security measures, tailored to a specific DBMS system. This involves the actual programming of the
database, taking into account the features
and limitations of the DBMS and the client.
Answer A is incorrect. Logical database design is the process of creating a data model of an
enterprise based on a specific data model,
but independent of a particular DBMS. In the logical database design stage, users can define tables
and relationships that reflect the
conceptual design.
Answer C is incorrect. Database design is the process of creating a design for a database that will
support the enterprise’s operations
and objectives for the required database system. It represents data and relationships between data
required by all major application areas
and user groups.
Answer B is incorrect. Conceptual database design is the process of constructing a model for the
data at a high level of abstraction
without using DBMS. It consists of the construction of an Entity-Relationship schema, providing an
optimal description of the user
requirements.
During the physical design process, you convert the data gathered during the logical design phase into a description of the physical database, including tables and constraints. Physical design decisions, such as the type of index or partitioning have a large impact on query performance.